Vinyl chloride polymers and compositions for additive manufacturing

ABSTRACT

The present disclosure is directed to a thermoplastic polymer for additive manufacturing, wherein the thermoplastic polymer is derived from a chlorinated monomer unit, wherein the thermoplastic polymer has a melt flow rate (MFR) suitable for additive manufacturing. The present disclosure is also directed to a method of making a 3D product formed by additive manufacturing, wherein the 3D product comprises a thermoplastic polymer derived from a chlorinated monomer unit or a thermoplastic composition comprising at least one thermoplastic polymer derived from a chlorinated monomer unit; and at least one stabiliser, wherein the thermoplastic polymer or composition has a MFR suitable for additive manufacturing.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This Application is a Divisional Application of U.S. application Ser.No. 15/770,146, filed Apr. 20, 2018 (allowed), which is a National PhaseApplication under 35 U.S.C. § 371 of PCT International Application No.PCT/IB2016/001580, filed Oct. 21, 2016, which claims the benefit andpriority of Australian Application No. 2015904359, filed Oct. 23, 2015.The entire contents of these applications are incorporated herein byreference.

FIELD OF THE INVENTION

The present invention relates to chlorinated thermoplastic polymers foruse in additive manufacturing (3D printing). In particular, theinvention relates to chlorinated thermoplastic polymers andthermoplastic compositions comprising at least one thermoplastic polymerderived from a chlorinated monomer unit; and to a method of forming 3Dproducts using 3D printing with such thermoplastics.

BACKGROUND TO THE INVENTION

3D printing is a widely used and evolving processing technique. The term“3D printing” summarises a large variety of ever evolving technologies,covering for example, metal-laser sintering, plastic powder sintering,UV curing and molten layer deposition techniques. A general overview ofthe techniques applied in this rapidly evolving application field isbest provided by a search on the internet, as printed media hasdifficulties keeping up with the fast pace of evolving developments.

At its core, 3D printing is generally a process in which athree-dimensional structure is formed by the cumulative fusion ofdiscreet particles (such as plastics and metals) layer by layer.

An example of a common technique for layering molten plastic to form 3Dproducts is fused deposition modelling (FDM), which is also known asfused filament fabrication (FFF). This technique allows one or moreplastic materials to be heated and deposited for cooling to form a 3Dproduct. Due to the particular requirements for the FDM technology, thepreferred polymers used as the printing material are acrylonitrilebutadiene styrene (ABS) and polylactic acid (PLA). Other materials suchas polycarbonates (PC), polyamides (PA) and polystyrenes (PS) areavailable, and more recently, polyether ether ketones (PEEK).

The commonly used ABS and PLA materials have several functionalshortcomings. For example, ABS contracts as it cools, and therefore canbe prone to “bowing” and/or “warping”, which may result inmal-formations, and is very difficult to use without a heated bed. ABSdissolves in acetone and it, as well as PLA both absorb water from theair and therefore requires oven drying prior to use or storage inspecial containers to avoid water absorption. PLA also has a slowcooling rate and thus requires a cooling fait during use. It can alsowarp at about 50° C. Since PLA is made from organic materials, such ascorn, it is biodegradable and is not as strong as ABS. Accordingly,characteristics such as the above as well as outdoor weatheringperformance, mechanical strength and flame retardancy are just some ofthe properties in need of improvement in new 3D printing materials.

Research has been undertaken to discover better performing 3D printableraw materials. Many past attempts have focussed on the use of differentgrades of engineering plastics, which have already been used, forexample, in injection moulding. 3D printing-specific polymermodifications of such plastics have been introduced recently as a result(e.g. Ultem grades by Stratasys®).

WO2010108076 describes a new biopolymer with improved impact strength,based on the crosslinking of biodegradable polymer chains.

U.S. Pat. No. 7,365,129 describes a new method of 3D printing frompowders. The thermoplastic polymers disclosed in this US Patent includePVC as one of the possible powder raw materials. However, this powderfusion technology is not comparable with fused deposition modelling(FDM) 3D printing. No further details of the PVC powder are provided inthis US Patent.

WO 9826013 describes inks for ink jet printing. The inks are composed ofan ester amide resin, a “tackifying resin”, and a colorant. The esteramide resin is composed of polymerized fatty acids that have beencombined with long chain monohydric alcohols and diamines. PVC ismentioned as a “tackifying” resin component.

Although chlorinated thermoplastics, such as PVC have been disclosed inconnection with 3D printing as discussed above, such chlorinatedthermoplastics are yet to be used in general 3D printing applicationsfor inclusion as common plastic raw materials.

In view of the growth of 3D printing, such as the fused depositionmodelling (FDM) technique, in private home 3D printing, as well as inindustrial applications (e.g., Arburg Freeformer and Big Area AdditiveManufacturing (BAAM) technology) and the restriction in choice ofalternative suitable polymers, the inventors set out to make available acost competitive polymer with excellent properties that make it suitablefor industrial as well as home use.

Thus, it would be beneficial to introduce another thermoplastic polymeras a building block for the 3D printing industry, which provides atleast an improvement in any one or more of the characteristics of known3D printable materials or at least provides different, and in many casesimproved physical features and mechanical characteristics, when comparedto those currently in use.

The invention disclosed herein seeks to alleviate any one or more of thedisadvantages known in the art, or at least to provide an alternativethermoplastic polymer that may be suitable for forming structures withdifferent and/or durable characteristics.

Any prior art reference or statement provided in the specification isnot to be taken as an admission that such art constitutes, or is to beunderstood as constituting, part of the common general knowledge.

SUMMARY OF THE INVENTION

In one broadest form, the invention relates to a novel chlorinatedthermoplastic polymer for additive manufacturing (3D printing).

In a first aspect, the present invention provides a thermoplasticpolymer for additive manufacturing, wherein the thermoplastic polymer isderived from a chlorinated monomer unit, wherein the thermoplasticpolymer has a melt flow rate (MFR) suitable for additive manufacturing.A suitable MFR may be determined at 205° C. according to ASTM D1238.

In a second aspect, the present invention provides a thermoplasticcomposition for additive manufacturing, wherein the thermoplasticcomposition comprises at least one thermoplastic polymer derived from achlorinated monomer unit and at least one stabiliser, wherein thethermoplastic composition has a melt flow rate (MFR) suitable foradditive manufacturing. A suitable MFR may be determined at 205° C.according to ASTM D1238.

In one embodiment of the second aspect, the thermoplastic compositionfurther comprises at least one lubricant.

In another embodiment of the first or second aspect, the MFR is from 0.5to 30, as determined at 205° C. according to ASTM D1238. Preferably theMFR is from 2 to 20, as determined at 205° C. according to ASTM D1238.More preferably, the MFR is from 5 to 15, as determined at 205° C.according to ASTM D1238.

In another embodiment of the first or second aspect, the thermoplasticpolymer or thermoplastic composition has a relevant tensile strength. Asused herein the term “tensile strength” refers to the tensile strengthof the resulting 3D printed product comprising the thermoplastic polymeror thermoplastic composition. The term “relevant tensile strength” meansthat the thermoplastic polymer or thermoplastic composition is capableof forming a 3D printed product that does not substantially break apart,fracture and/or is non-cleaving during (or after) 3D printing processingconditions, while providing a physically robust end product.

In another embodiment of the first or second aspect, the tensilestrength of the thermoplastic polymer or thermoplastic composition isfrom about 15 to about 60 MPa. Preferably the tensile strength of thethermoplastic polymer or thermoplastic composition is from about 20 toabout 60 MPa. Most preferably the tensile strength of the thermoplasticpolymer or thermoplastic composition is about 30 MPa.

In another embodiment of the first or second aspect, the thermoplasticpolymer is polyvinyl chloride or the thermoplastic composition comprisespolyvinyl chloride (or CPVC). In this embodiment, the thermoplasticpolymer or the thermoplastic polymer in the thermoplastic composition isPVC (or CPVC) and may be optionally copolymerised with co-monomer unitsselected from ethylenically unsaturated carboxylic acids, ethylenicallyunsaturated carbonates, ethylenically unsaturated urethanes,ethylenically unsaturated alcohols, ethylenically unsaturated aromatics,alkyl acrylates alkyl methacrylates, ethylene vinyl alcohols, vinylacetates, styrenes, and hydroxyalkanoic acid wherein the hydroxyalkanoicacids have five or fewer carbon atoms including glycolic acid, lacticacid, 3-hydroxypropionic acid, 2-hydroxybutyric acid, 3-hydroxybutyricacid, 4-hydroxybutyric acid, 3-hydroxyvaleric acid, 4-hydroxyvalericacid, 5-hydroxyvaleric acid, or combinations of two or more thereof. Thealkyl groups of any co-monomer units may comprise any number of carbonunits sufficient to modify the molecular weight of the thermoplasticpolymer chain. In one embodiment, the alkyl groups of the alkylacrylates and alkyl methacrylates have from 1 to 10 carbon atoms. Inembodiments where the thermoplastic polymer comprises monomeric unitshaving carboxylic acid groups, at least a portion of the carboxylic,acid groups in the copolymer may be neutralized to salts with alkalimetal cations, alkaline earth metal cations, transition metal cations,or combinations thereof. The degree of neutralization may assist inmodifying the observed viscosity of the thermoplastic polymer or thethermoplastic composition and thus achieve the desired flow rate.

In another embodiment of the first or second aspect, the thermoplasticpolymer may be a blend of two or more thermoplastic materials selectedfrom polyolefins, polyhydroxyalkanoates (PHA), polyesters includingpolyethylene terephthalates (PET), polyester elastomers, polyamides (PA)including nylons, polystyrenes including styrene maleic anhydrides (SMA)and acrylonitrile butadiene styrene (ABS), polyketones, polyvinylchlorides (PVC), chlorinated polyvinyl chlorides (CPVC), polyvinylidenechlorides, acrylic resins, vinyl ester resins, polyurethane elastomersand polycarbonates (PC). In embodiments where a blend of thermoplasticmaterials is utilised, at least one of the thermoplastic materials is apolymer derived from a chlorinated monomeric unit.

In another embodiment of the first or second aspect, the thermoplasticpolymer is a blend of polyvinyl chloride (or CPVC) and polyolefinwherein the polyolefin is linear low-density polyethylene, low-densitypolyethylene, middle-density polyethylene, high-density polyethylene,ethylene-vinyl acetate copolymer, ethylene-alkyl acrylate copolymer,ethylene-propylene copolymer, polypropylene, propylene-α-olefincopolymer, polybutene, polypentene, chloropolyethylene,chloropolypropylene, or combinations of two or more thereof.

In another embodiment of the first or second aspect, the thermoplasticpolymer is polyvinyl chloride and has a K-value of between about 40 andabout 80. The polyvinyl chloride may have a K-value of 45 to 48, 50 to55, 58 to 60, 62 to 65, 66 to 68, 70 to 71, and 80. Preferably, theK-value is about 45, about 50, about 57 or about 71.

In another embodiment of the first or second aspect, the thermoplasticpolymer or thermoplastic composition comprises any one or more of lowand high molecular weight plasticisers (preferably low VOCplasticisers), higher molecular weight polymers, compatibilisers,fillers, reinforcing agents, pigments, modifiers and processing aids,release agents, flame retardants, anti-microbial additives andfungicides, blowing agents, conductivity agents, wood fibres, bamboo,chalk, metals and other additives.

In another embodiment of the first or second aspect, the at least onestabiliser is substantially free of lead, cadmium and/or barium.

In another embodiment of the first or second aspect, the thermoplasticpolymer or thermoplastic composition is provided in the form of powders,powder-blends, pellets, granules or filaments.

In another embodiment of the first or second aspect, the thermoplasticpolymer or thermoplastic composition is used in fused depositionmodelling (FDM) printing or a fused filament fabrication (FFF) printing.

In a third aspect, the present invention provides a method of making a3D product with an additive manufacturing machine, the method comprisingthe step of forming a product comprising the thermoplastic polymer orthermoplastic composition according to any one or more of the aboveembodiments of the first or second aspects.

In another embodiment of the third aspect, the additive manufacturingmachine utilises a fused deposition modelling (FDM) or a fused filamentfabrication (FFF) technique.

In a fourth aspect, the present invention provides a method of making a3D product formed by additive manufacturing, wherein the 3D productcomprises a thermoplastic polymer derived from a chlorinated monomerunit, wherein the thermoplastic polymer has a melt flow rate (MFR)suitable for additive manufacturing.

In a fifth aspect, the present invention provides a method of making a3D product formed by additive manufacturing wherein the 3D productcomprises a thermoplastic composition comprising at least onethermoplastic polymer derived from a chlorinated monomer unit and atleast one stabiliser, wherein the thermoplastic composition has a meltflow rate (MFR) suitable for additive manufacturing.

In one embodiment of the fifth aspect, the thermoplastic compositionfurther comprises at least one lubricant.

In another embodiment of the fourth or fifth aspect, the 3D productcomprises the thermoplastic polymer or thermoplastic compositionaccording to any one or more of the above embodiments of the first orsecond aspects.

In a sixth aspect, the present invention provides a 3D product formed byadditive manufacturing, wherein the 3D product comprises a thermoplasticpolymer derived from a chlorinated monomer unit, wherein thethermoplastic polymer has a melt flow rate (MFR) suitable for additivemanufacturing.

In a seventh aspect, the present invention provides a 3D product formedby additive manufacturing, wherein the 3D product comprises athermoplastic composition comprising at least one thermoplastic polymerderived from a chlorinated monomer unit and at least one stabiliser,wherein the thermoplastic composition has a melt flow rate (MFR)suitable for additive manufacturing.

In one embodiment of the sixth or seventh aspect, the 3D productcomprises the thermoplastic polymer or thermoplastic compositionaccording to any one or more of the above embodiments of the first orsecond aspects.

The nature of the invention will become apparent to the person skilledin the art reading the detailed description of the embodiments,preferred embodiments and most preferred embodiments as describedherein.

DETAILED DESCRIPTION OF THE INVENTION

Where the terms “comprise”, comprises”, “comprising”, “include”,“includes”, “included” or “including” are used in this specification,they are to be interpreted as specifying the presence of the statedfeatures, integers, steps or components referred to, but not to precludethe presence or addition of one or more other feature, integer, step,component or group thereof.

As used herein, the teen “derived from” in the context of polymers meansthat the specified monomeric unit is at least one of the monomeric unitsincluded in the polymer chain. The term is not limited to mean that thespecified monomeric unit is the only monomeric unit in the polymerchain. Additionally, the term does not limit the monomeric unit to be aderivative thereof.

As used herein the term “tensile strength” refers to the tensilestrength of the resulting 3D printed product comprising thethermoplastic polymer or thermoplastic composition.

As used herein, the term “relevant tensile strength” means that thethermoplastic polymer or thermoplastic composition is capable of forminga 3D printed product that does not substantially break apart, fractureand/or is non-cleaving during (such as demoulding from the printerbase), or after, the 3D printing process.

As used herein, the term “suitable for additive manufacturing” meansthat the thermoplastic polymer or thermoplastic composition does notdegrade under 3D printing processing conditions.

Also, the indefinite articles “a” and “an” preceding an element orcomponent of the invention are intended to be non-restrictive regardingthe number of elements or components. Therefore, the words “a” or “an”should be read as including one or at least one, and the singular wordform of the element or component also includes the plural, unless thenumber is obviously meant to be singular.

The following description refers to specific embodiments of the presentinvention and is in no way intended to limit the scope of the presentinvention to those specific embodiments.

According to one embodiment of the present invention the thermoplasticpolymer comprises at least one thermoplastic polymer derived from achlorinated monomer unit, wherein the thermoplastic polymer has a meltflow rate (MFR) suitable for additive manufacturing.

According to another embodiment of the present invention thethermoplastic composition comprises at least one thermoplastic polymerderived from a chlorinated monomer unit and at least one stabiliser,wherein the thermoplastic composition has a melt flow rate (MFR)suitable for additive manufacturing. Preferably, the thermoplasticcomposition comprises at least one lubricant.

A suitable MFR may be determined at 205° C. according to ASTM D1238.

A suitable MFR provides a melt flow of the thermoplastic polymer orthermoplastic composition that allows suitable fluidity for the meltdeposition step in 3D printing.

In some embodiments, the thermoplastic polymer or thermoplasticcomposition is in form of filaments, pellets, granules, powders orpowder blends. The form of the thermoplastic polymer or thermoplasticcomposition should be dictated by the type of 3D printer to be usedand/or the 3D printing technique to be utilised. For example, for FDM 3Dprinting using the thermoplastic polymer or thermoplastic composition ofthe present invention the thermoplastic polymer or thermoplasticcomposition is in the form of filaments, or extruded in-situ as a partof the 3D printing deposition process.

The thermoplastic polymer or thermoplastic composition of the presentinvention is highly versatile and may have a specific average molecularweight suitable for its intended purpose. As will be known to those inthe art, the average molecular weight will be dictated by thedistribution of polymers of varying molecular weights such as a high,mid or low average molecular weight distribution.

In one preferred embodiment, the thermoplastic polymer or thermoplasticcomposition comprises polyvinyl chloride (PVC) and/or chlorinatedpolyvinyl chloride (CPVC). It would be understood that the chlorinecontent of CPVC should generally be about 56 to 74% by mass. However,the chlorine content of most commercially available CPVC is about 63 to69% by mass. In this preferred embodiment, the PVC and/or CPVC may beused as the base polymer (i.e., a copolymer or a component of a polymerblend) or may be the sole polymer (i.e., a homopolymer). When ahomopolymer of PVC is used, it may be selected from the commerciallyavailable PVC, which comes in various molecular weights and which arecharacterised by a K-value. In a preferred embodiment, the K-value maybe 40 to 45, 50 to 55, 58 to 60, 62 to 65, 66 to 68, 70 to 71 and 80. Ina most preferred embodiment, the K-value is from 45 to 71 In thisembodiment, the thermoplastic polymer or thermoplastic compositioncomprising polyvinyl chloride (PVC), either as a copolymer (includingpolymer blends) or homopolymer, may be modified by incorporating one ormore auxiliaries, modifiers, processing aids, additives and functionaladditives to impart desired characteristics and/or properties.

Generally, the thermoplastic polymer or thermoplastic composition of thepresent invention may comprise one or more additives. The inclusion ofadditives may influence the overall melt flow characteristics. Certainadditives may increase the viscosity and thereby reduce melt flow,whilst certain additives may decrease the viscosity and thereby increasemelt flow. The addition of additives may also influence, and in somesituations may interfere with other characteristics and/or desiredproperties such as, but not limited to, hardness and stiffness, surfacegloss, interlayer adhesion, bowing and shrinkage.

The versatility of the thermoplastic polymer or thermoplasticcomposition of the present invention allows it to be used in a largevariety of 3D printing applications, including but not limited to,modelling, prototyping, rigid pipes, profiles, rigid pharma packaging,semi-flexible pharma packaging, flexible cables, soft bags and assorted3D-printed polymer items, such as toys, plastic devices, gadgets,discrete objects, and “polymer-widgets”.

The inventors have identified an unusual requirement of thethermoplastic polymer or thermoplastic composition of the presentinvention, in the requirement of good inter-layer adhesion between thenon-pressure applied layers, for example, as in 3D FDM printing. Mostplastics processing is done under high pressure and shear conditions. Inorder to withstand these processing conditions, certain thermoplasticpolymers, such as PVC and CPVC are best used as a thermoplasticcomposition blended with heat stabilisers and lubricants, which providethe release properties front the hot metal processing surfaces. Thestabilisers and lubricants that are essential for normal processingusing generally available thermoplastic polymers were found to severelyaffect the inter-layer adhesion requirements under the additivemanufacturing processing conditions required for 3D FDM printing.

Since certain chlorinated thermoplastic polymers, such as PVC and CPVC,are prone to degradation at high temperatures and therefore cannot beprocessed adequately without addition of stabilisers and lubricants,currently used formulations in non-3D printing applications have provento be unsuitable for adequate 3D printing.

It was thus found that certain chlorinated thermoplastic polymers andcompositions (such as PVC and CPVC compositions) needed to provide alower than usual melt viscosity. The lower melt viscosity may be basedon lower molecular weight thermoplastic polymers, or as thermoplasticcopolymers. In some cases, the thermoplastic polymer or thermoplasticcomposition may be in combination with additives such as plasticisersand/or process aids in the correct amounts to achieve acceptable 3Dprinting results.

The “melt flow index” (MFI) typically measured in thermoplastics byestablishing a “Melt Flow Rate” is not normally used to definechlorinated thermoplastic polymer or composition properties, such as PVCor PVC composition properties because the flow behaviour under lowpressure is not suitable to sufficiently characterise standard PVCprocessing properties.

For chlorinated thermoplastic polymers, such as PVC, specialrequirements are defined for measuring the MFR. For PVC, MFR is normallydetermined using ASTM D3364. Contrary to these typical PVC requirements,it was surprisingly found that the properties needed for PVC 3D printingcompositions allowed them to be characterised by the standard methodsused for normal flowing thermoplastic polymers, according to ASTM D1238,Procedure A or ISO 1133 Procedure A and thus being atypical for PVC.

It was found that in order to 3D print chlorinated thermoplastics, suchas PVC and CPVC, the PVC/CPVC composition is to have a melt viscosity,as determined according to ASTM D1238 Procedure A in the Melt How Rate(MFR) range of 0.5 to 30, preferably 2 to 20, more preferably 5 to 15,measured according to ASTM D1238, Procedure A, at 205° C. with a 2.16 kgnominal weight and a die of bore diameter=2.0955+/−0.0051 mm, borelength 8+/−0.025 mm. The MFR of PLA has been approximated to be 7 to 9at 195° C.; whilst the MFR of ABS has been approximated to be 8 to 10 at230° C., when compared against the MFR of the chlorinated thermoplasticpolymer or thermoplastic composition of the present invention.

For FDM 3D printing, adequate adhesion between the 3D printed layers(i.e., inter-layer adhesion) is an important requirement. This isbecause good layer adhesion results in a product with homogeneousmechanical properties, which in the case of rigid products maydemonstrate “brittle failure” behaviour, not aligned to the melt-layerand flow direction. A semi-flexible or flexible product may “tear” in anamorphous manner.

The thermoplastic polymer or thermoplastic composition preferably hassuitable adhesion between the relatively pressure-free applied meltlayers for printing the resulting 3D product and to achieve the desiredmechanical properties. Most preferably, the thermoplastic polymer orthermoplastic composition provides excellent overall definition, lowwarpage and dimensional stability compared to the reference digital 3Dproduct model. The thermoplastic polymer or thermoplastic compositioncomprising the chlorinated thermoplastic polymer adheres with otherpolymers including, but not limited to, acrylonitrile-butadiene-styrene(ABS), acrylonitrile-styrene-acrylate (ASA), cellulose acetate (CA),polycarbonate (PC), poly(methyl methacrylate) (PMMA), polybutyleneterephthalate (PBTP), thermoplastic polyimide (TPI) and styreneacrylonitrile (SAN).

The layer adhesion can be influenced by many parameters, such asprinting temperature, printing speed and layer thickness. Whereas theseparameters are influenced by the printing process settings, whilst theactual chlorinated thermopolymer (e.g., PVC) based composition has astrong influence on the inter-layer adhesion, being much more adhesivethan the composition of the alternative thermoplastics currently used in3D FDM printing.

It was found that the chlorinated thermopolymer or thermopolymercomposition (e.g., PVC/CPVC), with the MFR as described herein, alsopreferably needs to provide good overall inter-layer adhesion to achievesuitable 3D FDM printed products. A good inter-layer adhesion may beobserved by a high tensile strength coupled with a homogenousbrittle-failure behaviour of a 3D-printed product.

The chlorinated thermopolymer or thermopolymer composition (PVC)correctly formulated for 3D-printing applications according to thepresent invention having a low MFI range possesses a highly stable, truethermo-plasticity with far less theological behaviour as compared tonormally available chlorinated thermopolymer (e.g., PVC) compositionsmarketed for use in non-3D printing applications.

The inventors have identified that when the conventional ratios andlevels of stabilising components are applied at commonly recommendedlevels, the stabilising components do not provide a useful thermoplasticcomposition suitable for 3D printing.

The inventors have also identified that reducing the inter-layeradhesion does not allow the continuous build up of thermopolymer toachieve a strong and/or robust 3D product. Furthermore, the inventorshave identified that the tensile strength, as measured according totensile test standards ASTM D638, provides a measurable relativeadhesive strength of a 3D printable product.

The at least one stabiliser used in the thermoplastic composition of thepresent invention preferably include stabilizers that are suitablycompatible with chlorinated thermoplastic polymers (such as PVC andCPVC). Stabilisers are essential because these prevent or at leastreduce decomposition of the chlorinated thermopolymer by releasinghydrogen chloride, for example when the thermopolymer is PVC.Representative examples of stabilisers for 3D printable compositions ofchlorinated thermoplastic polymers (e.g., PVC) are selected from PVCstabilisers known in the PVC industry comprising any one or more of tin,lead, cadmium, mixed metals including rare earths, calcium/zinc andorganic stabilisers.

It should be understood that stabilisers comprising metals based onlead, barium and cadmium should be avoided, if possible, due to theirinherent toxicity to living organisms, such as mammals and humans.Additionally, sulfur-tin based stabilisers that are commonly availableshould also be avoided, if possible, due to their potential volatilityduring 3D processing conditions and the resulting unpleasant sulphursmell.

The choice of stabiliser may depend on several factors, such as thetechnical requirements of the thermoplastic polymer and any regulatoryapproval requirements of any specific country or jurisdiction, and thecost of the stabiliser may also be a factor.

In some embodiments, co-stabilisers may be utilised. Theseco-stabilisers may be the same as the stabilisers as described above andmay provide a synergistic effect and provide an enhanced performance incertain circumstances.

The stabilisers that provide the most favourable thermoplasticcompositions for 3D printing are stabilisers based on mixed metals, suchas calcium-zinc stabilisers, and zinc-free organic stabiliser systems,commonly called organic-based stabiliser (OBS®, COS, HMF) systems.

Some representative examples of tin stabilisers aremethyl-tin-mercaptides, butyl-tin-mercaptides, octyl-tin-mercaptidesreverse-ester tin stabilisers, tin-maleates, and tin-carboxylates.

Mixed metal stabilisers are often complex mixtures of many (possible)components, especially for the preferred stabiliser systems. Somerepresentative examples of the components in mixed metal stabilisers aremetal soaps of sodium, calcium, magnesium, zinc, rare earths such aslanthanum and cerium, and other metals such as lead, cadmium and barium.The soap component may be based on naturally occurring or syntheticfatty acids of various chain lengths including C₈ to C₄₀ such as C₁₈(oleic, stearic, and linoleic acids), C₂₀ (eicosapentaenoic acid), C₂₂(docosahexaenoic acid), and C₂₈ (montanic acids), and other acids suchas benzoic acid and adipic acid. In some embodiments, soapsincorporating a more than stoichiometric amount of metal (e.g., basic orover-based soaps) may be included.

In some embodiments, the metal soap combinations may be combined withsynergistically active components, such as polyols. Representativeexamples of polyols that may be used in the thermoplastic compositionsof the present invention include, but are not limited to,pentaerythritol, dipentaerythritol, tripentaerythritoltris(hydroxyethyl) isocyanurate (THEIC), trimethylol propane (TMP),bis-trimethylol propane, inositol, polyvinylalcohol, sorbitol, maltitol,iso-maltitol, mannitol, and lactose. Partial esters of polyols withfatty acids or oligomeric polyol-polyacid compounds may be used asstabilising components (e.g. Plenlizer grades).

In some embodiments, the metal soap combinations may be combined withinorganic co-stabilisers. Representative examples of inorganicco-stabilisers include, but are not limited to, metal oxides, hydroxidesand salts (such as perchlorate or superacid-salts), hydrotalcites,hydrocalumites, calcium-hydroxy-aluminium-phosphites (CHAP), katoites,dawsonites, calcium aluminium hydroxycarbonates (CAHC) and zeolites.Other inorganic co-stabilisers that may be used and that are compatiblewith the present thermoplastic compositions are described in literaturerelating to PVC.

In some embodiments, the metal soap combinations may be combined withorganic co-stabilisers. Representative examples of organicco-stabilisers include, but are not limited to, beta-diketones andbeta-keto-ester costabilisers, such as 1,3-diketones (including alkali,alkali earth and zinc chelates thereof), dibenzoylketones,stearoylbenzoylketones acetylacetones, beta-keto esters, dihydroaceticacids and acetoacetic acid esters, and malonic acids and its esters.

In some embodiments, the metal soap combinations may be combined withdihydropyridines and polydihydropyridines. Representative examples ofdihydropyridines and polydihydropyridines are described in EP286887, andinclude dimethyl aminouracil (DMAU) and didodecyl1,4-dihydro-2,6-dimethylpyridine-3,5-dicarboxylate.

In some embodiments, the metal soap combinations may be combined withepoxides and glycidyl compounds. Representative examples of epoxides andglycidyl compounds include, but are not limited to, epoxidised fattyacid esters and oils (e.g., ESBO, epoxidised linseed oil), glycidylethers of bisplienol A, THEIC and other polyols.

In some embodiments, the metal soap combinations may be combined withorganic phosphites. Representative examples of organic phosphitesinclude, but are not limited to, arylalkyl phosphites (e.g.diphenylisodecyl phosphite, DPDP), trialkyl phosphites (e.g. triisodecylphosphite, TDP), thiophosphites and thiophosphates, Other examples oforganic phosphites are disclosed in ‘International Plastics Handbook’,Hanser Publishing Munich, 2006, ISBN 3-56990-399-5; ‘Plastics AdditivesHandbook’, Hanser Publishing Munich, 2001, ISBN 3-446-19579-3; and ‘PVCHandbook’, Hanser Publishing Munich, 2005, ISBN 3-446-22714-8.

In some embodiments, the metal soap combinations may be combined withmercaptoesters and thio-compounds. Representative examples ofmercaptoesters and thio-compounds include, but are not limited to,capped mercaptide technology (Advastab NEO products) and those that aredescribed in EP768336.

In some embodiments, the metal soap combinations may be combined withantioxidants. Representative examples of antioxidants include, but arenot limited to, organic sulphides, ionol (BHT), Irganox 1076 and Irganox1010, and Santhowhite Powder. Other antioxidants that may be used in thepresent thermoplastic composition are disclosed in the ‘PlasticsAdditives Handbook’, Hamer Publishing Munich, 2001, ISBN 3-446-19579-3.

In some embodiments, the metal soap combinations may be combined withUV-stabilisers. Representative examples of UV-stabilisers include, hutare not limited to, the so-called HALS-compounds with trade names suchas Cimasorb, Tinuvin and Univul. Other UV-stabilisers that may be usedin the present thermoplastic composition are disclosed in the ‘PlasticsAdditives Handbook’, Hanser Publishing Munich, 2001, ISBN 3-446-19579-3.

Preferred stabilising components can be any combination described in theliterature, such as calcium-based stabilising systems, lead-basedstabilising systems, barium-zinc-based stabilising systems,calcium-zinc-based stabilising systems, tin-based stabilising systems.The stabilizing systems with heavy-metals such as lead, barium andcadmium components may be suitable but not preferred for ecologicalreasons as a result of their heavy metal content. In some preferredembodiments, Ba—Zn stabilisers and Ca—Zn stabilisers may be used asmetallic soaps (e.g., stearates), while in some embodiments, Snstabilisers may be used as organic tin compounds (e.g., dialkyl tincompounds). In other embodiments, Pb stabilisers may be used as basicsulphate, basic carbonate, or basic phosphate.

Some examples of stabilising components include, but are not limited to,any one or more of the perchlorate compounds, glycidyl compounds,beta-diketones, beta-keto esters, dihydropyridines,polydihydropyridines, polyols, disaccharide alcohols, stericallyhindered amines (such as tetraalkylpiperidine compounds), alkalialuminosilicates (such as zeolites), hydrotalcites and alkalialuminocarbonates (such as dawsonites), alkali (or alkaline earth-)carboxylates, -(bi)carbonates or -hydroxides, antioxidants, lubricantsor organotin compounds which are suitable for stabilisingchlorine-containing polymers, especially PVC.

In one preferred embodiment, the stabilising component is a perchloratecompound of formula M(ClO₄)_(n), wherein M is Li, Na, K, Mg, Ca, Sr, Zn,Al, La or Ce and n is 1, 2 or 3, based on the nature of M. Theperchlorate salts may be complexed with alcohols (such as polyols and/orcyclodextrins), ether alcohols or ester alcohols. The alcohols includingthe polyhydric alcohols or polyols may be in their dimeric, trimeric,oligomeric and polymeric forms, such as di-, tri-, tetra- andpoly-glycols, and di-, tri- and tetra-pentaerythritol, or polyvinylalcohol in various degrees of polymerisation. It would be understoodthat the perchlorate salts may be introduced in a variety of forms, forexample, in the form of a salt or an aqueous solution applied to thethermoplastic component, such as PVC, or to any one or more of thesubstrate additives, calcium silicate, zeolites or hydrotalcites, orbound in a hydrotalcite by chemical reaction. Glycerol monoethers andglycerol monothioethers may be preferred as polyol partial ethers.

In certain embodiments, when the stabilizing component is a perchlorate,the percholates can be used in an amount of, for example, from 0.001 to5, preferably from 0.01 to 3, more preferably from 0.01 to 2, parts byweight, based on 100 parts by weight of the thermoplastic component,such as PVC.

In another preferred embodiment, the stabilising component is a glycidylcompound.

In another preferred embodiment, the stabilising component is a1,3-dicarbonyl compounds such as beta-diketone or beta-keto ester.Suitable examples of 1,3-dicarbonyl compounds and their alkali metal,alkaline earth metal and zinc chelates are acetylacetone,butanoylacetone, heptanoylacetone, stearoylacetone, palmitoylacetone,lauroylacetone, 7-tert-nonylthio-heptane-2,4-dione, benzoylacetone,dibenzoylmethane, lauroylbenzoylmethane, palmitoyl-benzoylmethane,stearoyl-benzoylmethane, isooctylbenzoylmethane,5-hydroxycapronyl-benzoylmethane, tribenzoylmethane,bis(4-methylbenzoyl)methane, benzoyl-p-chlorobenzoylmethane,bis(2-hydroxybenzoyl)methane, 4-methoxybenzoyl-benzoylmethane,bis(4-methoxybenzoyl)methane, 1-benzoyl-1-acetylnonane,benzoyl-acetylphenylmethane, stearoyl-4-methoxybenzoylmethane,bis(4-tert-butylbenzoyl)methane, benzoyl-formyl ethane,benzoyl-phenylacetylmethane, biscyclohexanoyl-methane,di-pivaloyl-methane, 2-acetyleyclopentanone, 2-benzoylcyclopentanone,diacetoacetic acid methyl, ethyl and allyl ester, benzoyl-, propionyl-and butyryl-acetoacetic acid methyl and ethyl ester, triacetylmethane,acetoacetic acid methyl, ethyl, hexyl, octyl, dodecyl or octadecylester, benzoylacetic acid methyl, ethyl, butyl, 2-ethylhexyl, dodecyl oroctadecyl ester, and propionyl- and butyryl-acetic acid C1 -C18 alkylester. Stearoylacetic acid ethyl, propyl, butyl, hexyl or octyl esterand polynuclear beta-keto esters as described in EP 433 230 anddehydroacetic acid and the zinc, magnesium or alkali metal saltsthereof.

The 1,3-diketo compounds may be used in an amount of, for example, from0.01 to 10, preferably from 0.01 to 3, and more preferably from 0.01 to2, parts by weight, based on 100 parts by weight of the thermoplasticcomponent, such as PVC.

In another preferred embodiment, the stabilising component is adihydropyridine or a polydihydropyridine. Suitable dihydropyridine andpolydihydropyridine are described in, for example, EP 2007, EP 0 362012, EP 0 286 887, EP 0 024 754, EP 0 286 887.

In another preferred embodiment, the stabilising component is a polyolor disaccharide alcohol. Suitable examples of polyol and disaccharidealcohol include, but are not limited to, pentaerythritol,dipentaerythritol, tripentaerythritol, bistrimethylolpropane,bistrimethylolethane, trismethylolpropane, inosite, polyvinylalcohol,sorbitol, maltite, isomaltite, lactite, lycasin, mannitol, lactose,leucrose, tris(hydroxyethyl) isocyanurate, palatinite,tetramethylolcyclohexanol, tetramethylolcyclopentanol,tetramethylolcyclopyranol, glycerol, diglycerol, polyglycerol,thiodiglycerol or 1-0-a-D-glycopyranosyl-D-mannitol dihydrate. Of thesecompounds disaccharide alcohols may be preferred.

The polyols and disaccharide alcohols may be used in an amount of, forexample, from 0.01 to 20, preferably from 0.1 to 20, and more preferablyfrom 0.1 to 10, parts by weight, based on 100 parts by weight of thethermoplastic component, such as PVC.

In another preferred embodiment, the stabilising component is asterically hindered amine (such as tetraalkylpiperidine compounds). Thesterically hindered amines may also be light stabilizers. They may becompounds of relatively low molecular weight (<700) or of relativelyhigh molecular weight. In the latter case, they may be oligomeric orpolymeric products. The sterically hindered amines may preferably betetramethylpiperidine compounds having a molecular weight of more than700 that contain no ester groups.

Suitable examples of sterically hindered amines, such as thepolyalkyipiperidine compounds include, but are not limited to4-hydroxy-2,2,6,6-tetramethylpiperidine,1-allyl-4-hydroxy-2,2,6,6-tetramethylpiperidine,1-benzyl-4-hydroxy-2,2,6,6-tetramethylpiperidine,1-(4-tert-butyl-2-butenyl)-4-hydroxy-2,2,6,6-tetramethylpiperidine,4-stearoyloxy-2,2,6,6-tetramethylpiperidine,1-ethyl-4-salicyloyloxy-2,2,6,6-tetramethylpiperidine,4-methacryloyloxy-1,2,2,6,6-pentamethylpiperidine,1,2,2,6,6-pentamethylpiperidin-4-yl-β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, di(1-benzyl-2,2,6,6-tetramethylpiperidin-4-yl) maleinate,di(2,2,6,6-tetramethylpiperidin succinate,di(2,2,6,6-tetramethylpiperidin-4-yl) glutarate,di(2,2,6,6-tetramethylpiperidin-4-yl) adipate,di(2,2,6,6-tetramethylpiperidin-4-yl) sebacate,di(1,2,2,6,6-pentamethylpiperidin-4-yl) sebacate,di(1,2,3,6-tetramethyl-2,6-diethylpiperidin-4-yl) sebacate,di(1-allyl-2,2,6,6-tetramethylpiperidin-4-yl) phthalate,1-propargyl-4-beta-cyanoethyloxy-2,2,6,6-tetramethylpiperidine,1-acetyl-2,2,6,6-tetramethylpiperidin-4-yl acetate, trimellitic acidtri(2,2,6,6-tetramethylpiperidin-4-yl) ester,1-acryloyl-4-benzyloxy-2,2,6,6-tetramethylpiperidine, diethylmalonicacid di(2,2,6,6-tetramethylpiperidin-4-yl) ester, dibutylmalonic aciddi(1,2,2,6,6-pentamethylpiperidin-4-yl) ester,butyl-(3,5-di-tert-butyl-4-hydroxybenzyl)-malonic aciddi(1,2,2,6,6pentamethylpiperidin-4-yl) ester, dibenzyl-malonic aciddi(1,2,2,6,6-pentamethylpiperidin-4-yl) ester, dibenzyl-malonic aciddi(1,2,3,6-tetramethyl-2,6-diethyl-piperidin-4-yl) ester,hexane-1′,6′-bis(4-carbamoyloxy-1-n-butyl-2,2,6,6-tetramethyl-piperidine),toluene-2′,4′-bis(4-carbamoyloxy-1-n-propyl-2,2,6,6-tetramethylpiperidine),dimethyl-bis(2,2,6,6-tetramethylpiperidin-4-oxy)silane,phenyl-tris(2,2,6,6-tetramethylpiperidin-4-oxy)silane,tris(1-propyl-2,2,6,6-tetramethylpiperidin-4-yl)phosphite,tris(1-propyl-2,2,6,6-tetramethylpiperidin-4-yl) phosphate,phenyl-[bis(1,2,2,6,6-pentamethylpiperidin-4-yl)]phosphonate,4-hydroxy-1,2,2,6,6-pentamethylpiperidine,4-hydroxy-N-hydroxyethyl-2,2,6,6-tetramethylpiperidine,4-hydroxy-N-(2-hydroxypropyl)-2,2,6,6-tetramethylpiperidine,1-glycidyl-4-hydroxy-2,2,6,6-tetramethylpiperidine,N,N′-bis(2,2,6,6-tetramethylpiperidin-4-yl)hexamethylene-1,6-diamine,N,N′-bis(2,2,6,6-tetramethylpiperidin-4-yl)hexamethylene-1,6-diacetamide,N,N′-bis(2,2,6,6-tetramethylpiperidin-4-yl)hexamethylene-1,6-diformamide,1-acetyl-4-(N-cyclohexylacetamido)-2,2,6,6-tetramethylpiperidine,4-benzoylamino-2,2,6,6-tetramethylpiperidine,N,N′-bis(2,2,6,6-tetramethylpiperidin-4-yl)-N,N′-dibutyl-adipamide,N,N′-bis(2,2,6,6-tetramethylpiperidin-4-yl)-N,N′-dicyclohexyl-2-hydroxypropylene-1,3-diamine,N,N′-bis(2,2,6,6-tetramethylpiperidin-4-yl)-p-xylylene-diamine,N,N′-bis(2,2,6,6-tetramethylpiperidin-4-yl)succine-diamide,N-(2,2,6,6-tetramethylpiperidin-4-yl-beta-aminodipropionic aciddi(2,2,6,6-tetramethylpiperidin-4-yl) ester,4-(bis-2-hydroxyethyl-amino)-1,2,2,6,6-pentamethylpiperidine,4-(3-methyl-4-hydroxy-5-tert-butyl-benzoic acidamido)-2,2,6,6-tetramethylpiperidine,4-methacrylamido-1,2,2,6,6-pentamethylpiperidine,9-aza-8,8,10,10-tetramethyl-1,5-dioxaspiro[5.5]undecane,9-aza-8,8,10,10-tetramethyl-3-ethyl-1,5-dioxaspiro[5.5]undecane,8-aza-2,7,7,8,9,9-hexamethyl-1,4-dioxaspiro[4.5]decane,9-aza-3-hydroxymethyl-3-ethyl-8,8,9,10,10-pentamethyl-1,5-dioxaspiro[5.5]undecane,9-aza-3-ethyl-3-acetoxymethyl-9-acetyl-8,8,10,10-tetramethyl-1,5-dioxaspiro[5.5]undecane, 2,2,6,6-tetramethylpiperidine-4-spiro-2′-(1′,3′-dioxane)-5′-spiro-5″-(1″,3″-dioxane)-2″-spiro-4′″-(2′″,2′″,6′″,6′″-tetramethylpiperidine),3-benzyl-1,3,8-triaza-7,7,9,9-tetramethylspiro[4.5]decane-2,4-dione,3-n-octyl-1,38-triaza-7,7,9,9-tetramethylspiro[4.5]decane-2,4-dione,3-allyl-1,3,8-triaza-1,7,7,9,9-pentamethylspiro[4.5]decane-2,4-dione,3-glycidyl-1,3,8-triaza-7,7,8,9,9-pentamethylspiro[4.5]decane-2,4-dione,1,3,7,7,8,9,9-heptamethyl-1,3,8-triazaspiro[4.5]decane-2,4-dione,2-isopropyl-7,7,9,9-tetramethyl-1-oxa-3,8-diaza-4-oxo-spiro[4.5]decane,2,2-di-butyl-7,7,9,9-tetramethyl-1-oxa-3,8-diaza-4-oxo-spiro[4.5]decane,2,2,4,4-tetramethyl-7-oxa-3,20-diaza-21-oxo-dispiro[5.1.11.2]henicosane,2-butyl-7,7,9,9-tetramethyl-1-oxa-4,8-diaza-3-oxo-spiro[4.5]decane,8-acetyl-3-dodecyl-1,3,8-triaza-7,7,9,9-tetramethylspiro[4.5]decane-2,4dione,is(2,2,6,6-tetramethyl-piperidyl) sebacate,bis(2,2,6,6tetramethyl-piperidyl) succinate,bis(1,2,2,6,6-pentamethylpiperidyl) sebacate,n-butyl-3,5-di-tert-butyl-4-hydroxybenzyl-malonic acidbis(1,2,2,6,6,(pentamethylpiperidyl) ester, the condensation product of1-hydroxyethyl-2,2,6,6-tetramethyl-4-hydroxy-piperidine and succinicacid, the condensation product ofN,N′-bis(2,2,6,6-tetramethyl-4-piperidyl)-hexamethylenediamine and4-tert-octylamino-2,6-dichloro-1,3,5-s-triazine,tris(2,2,6,6-tetramethyl-4-piperidyl)nitrilotriacetate,tetrakis(2,2,6,6-tetramethyl-4-piperidyl)-1,2,3,4-butanetetraoate,1,1′-(1,2-ethanediyl)-bis(3,3,5,5-tetramethyl-piperazinone),4-benzoyl-2,2,6,6-tetramethylpiperidine,4-stearyloxy-2,2,6,6-tetramethylpiperidine,bis(1,2,2,6,6-pentamethylpiperidyl)-2-n-butyl-2-(2-hydroxy-3,5-di-tert-butylbenzyl)malonate,3-n-octyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro[4.5]decane-2,4-dione,bis(1-octyloxy-2,2,6,6-tetramethylpiperidyl) sebacate,bis(1-octyloxy-2,2,6,6-tetramethylpiperidyl) succinate, the condensationproduct of N,N′-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamineand 4-morpholino-2,6-dichloro-1,3,5-triazine, the condensation productof2-chloro-4,6-di(4-n-butylamino-2,2,6,6-tetramethylpiperidyl)-1,3,5-triazineand 1,2-bis(3-aminopropylamino)ethane, the condensation product of2-chloro-4,6-di(4-n-butylamino-1,2,2,6,6-pentamethylpiperidyl)-1,3,5-triazineand 1,2-bis(3-aminopropylamino)ethane,8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro[4.5]decane-2,4-dione,3-dodecyl-1-(2,2,6,6-tetramethyl-4-piperidyl)pyrrolidine-2,5-dione and3-dodecyl-1-(1,2,2,6,6-pentamethyl-4-piperidyl)-pyrrolidine-2,5-dione.

It would be understood by the skilled person that the amount ofsterically hindered amine added would depend on the desired degree ofstabilization sought. In the present invention, the amount of stericallyhindered amine stabiliser added may range from 0.01 to 0.5% by weight,preferably from 0.05 to 0.5% by weight, based on the thermoplasticcomponent, such as PVC, that has been added.

In another preferred embodiment, the stabilising component is ahydrotalcite or an alkali (alkaline earth) aluminosilicate (such aszeolites). Suitable examples of hydrotalcites include, but are notlimited to, Al₂O₃.6MgO.CO₂.12H₂O, Mg_(4.5)Al₂(OH)₁₃.CO₃.3.5H₂O,4MgO.Al₂O₃.CO_(2.9)H₂O, 4MgO.Al₂O₃.CO_(2.6)H₂O,ZnO.3MgO.Al₂O₃.CO_(2.8-9)H₂O and ZnO.3MgO.Al₂O₃.CO₂.5-6H₂O. Suitableexamples of zeolites (alkali and alkaline earth aluminosilicates)include, but are not limited to, Na₁₂Al₁₂Si₁₂O₄₈.27H₂O [zeolite A],Na₆Al₆Si₆O₂₄.2NaX.7.5H₂O where X═OH, Cl, ClO4, ½CO₃ [sodalite],Na₆Al₆Si₃₀O₇₂.24H₂O, Na₈Al₈Si₄₀O₉₆.24H₂O, Na₁₆Al₁₆Si₂₄O₈₀.16H₂O,Na₁₆Al₁₆Si₃₂O₉₆.16H₂O, Na₅₆Al₅₆Si₁₃₆O₃₈₄.250 H₂O [zeolite Y],Na₈₆Al₈₆Si₁₀₆O₃₈₄.264H₂O [zeolite X], and zeolites of the X and Y typehaving an Al/Si ratio of about 1:1, or the zeolites that can be formedby partial or complete replacement of the Na atoms by Li, K, Mg, Ca, Sr,Ba or Zn atoms, such as (Na,K)₁₀Al₁₀Si₂₂O₆₄.20H₂O,Ca_(4.5)Na₃[(AlO₂)₁₂(SiO₂)₁₂].30H₂O, K₉Na₃[(AlO₂)₁₂(SiO₂)₁₂].27H₂O.

In some embodiments, the zeolites listed may have lower water content ormay be anhydrous as described in J. Chem. Soc. 1952, 1561-1571, J. Chem.Soc. 1956, 2882, Am. Mineral. 54 1607 (1969), and in U.S. Pat. Nos.2,950,952, 4,503,023, 4,503,023.

The chemical composition of other hydrotalcites and an alkali (alkalineearth) aluminosilicates that may be suitable for use in the presentthermoplastic composition and may be found, for example, from patentspecifications U.S. Pat. No. 40,00,100, E1 062 813 and WO 93/20135.

The hydrotalcites and/or zeolites may be used in amounts of, forexample, from 0.1 to 20, preferably from 0.1 to 10, and most preferablyfrom 0.1 to 8, parts by weight, based on 100 parts by weight of thechlorinated thermoplastic polymer, such as PVC.

In another preferred embodiment, the stabilising component is an alkalialuminocarbonate (such as dawsonites). Those compounds that can be usedaccording to the present invention may be naturally occurring mineralsor synthetically prepared compounds. Suitable examples of naturallyoccurring alumino salt compounds include, but are not limited to,indigirite, tunisite, aluminohydrocalcite, para-aluminohydrocalcite,strontiodresserite and hydrostrontiodresserite. Other examples ofalumina salt compounds are potassium aluminocarbonate[(K₂O).(Al₂O₃).(CO₂)₂.2H₂O], sodium aluminothiosulfate[(Na₂O).(Al₂O₃).(S₂O₂)₂.2H₂O], potassium aluminosulfite[(K₂O),(Al₂O₃).(SO₂)₂.2H₂O], calcium aluminooxalate[(CaO).(Al₂O₂).(C₂O₂)₂.5H₂O], magnesium aluminotetraborate[(MgO).(Al₂O₃).(B₄O₆)₂.5H₂O],[([Mg_(0.2)Na_(0.6)]₂O).(Al₂O₃).(CO₂)₂.4.1H₂O],[([Mg_(0.2)Na_(0.6)]₂O).(Al₂O₃).(CO₂)₂.4.3H₂O] and[([Mg_(0.3)Na_(0.4)]₂O).(Al₂O₃).(CO₂)_(2.2).4.9H₂O]. Other alumino saltcompounds include, but are not limited to, M₂O.Al₂O₃.(CO₂)₂.pH₂O,(M₂O)₂.(Al₂O₃)₂.(CO₂)₂.pH₂O and M₂O.(Al₂O₃)₂.(CO₂)₂.pH₂O wherein M is ametal, such as Na, K, Mg_(1/2), Ca_(1/2), Sr_(1/2) or Zn_(1/2) and p isa number from 0 to 12.

The alkali aluminocarbonate dawsonites may also be substituted bylithium-aluminohydroxycarbonates orlithium-magnesium-aluminohydroxycarbonates, as described in EP 549,340.

The alkali aluminocarbonates may be used in an amount of, for example,from 0.01 to 10, preferably from 0.05 to 8, more preferably from 0.1 to5, parts by weight, based on 100 parts by weight of chlorinatedthermoplastic polymer, such as PVC.

In another preferred embodiment, the stabilising component is a zinccompound. Suitable examples of zinc compounds are the zinc salts ofmonovalent carboxylic acids, such as acetic acid, propionic acid,butyric acid, valeric acid, hexanoic acid, oenanthic acid, octanoicacid, neodecanoic acid, 2-ethylhexanoic acid, pelargonic acid, decanoicacid, undecanoic acid, dodecanoic acid, tridecanoic acid, myristic acid,palmitic acid, lauric acid, isostearic acid, stearic acid,12-hydroxystearic acid, 9,10-dihydroxystearic acid, oleic acid,3,6-dioxaheptanoic acid, 3,6,9-trioxadecanoic acid, behenic acid,benzoic acid, p-tert-butylbenzoic acid, dimethylhydroxybenzoic acid,3,5-di-tert-butyl-4-hydroxybenzoic acid, toluic acid, dimethylbenzoicacid, ethylbenzoic acid, n-propylbenzoic acid, salicylic acid,p-tert-octylsalicylic acid, and sorbic acid, zinc salts of divalentcarboxylic acids or the monoesters thereof, such as oxalic acid, malonicacid, succinic acid, glutaric acid, adipic acid, fumaric acid,pentane-1,5-dicarboxylic acid, hexane-1,6-dicarboxylic acid,heptane-1,7-dicarboxylic acid, octane-1,8-dicarboxylic acid,3,6,9-trioxadecane-1,10-dicarboxylic acid, lactic acid, malonic acid,maleic acid, tartaric acid, cinnamic acid, mandelic acid, malic acid,glycolic acid, oxalic acid, salicylic acid, polyglycol-dicarboxylicacid, phthalic acid, isophthalic acid, terephthalic acid andhydroxyphthalic acid; and the di- or tri-esters of tri- or tetra-valentcarboxylic acids, such as hemimellitic acid, trimellitic acid,pyromellitic acid, citric acid and the overbased zinc carboxylates.Other suitable examples of zinc compounds include, but are not limitedto, the zinc enolates such as enolates of acetylacetone, benzoylacetoneor dibenzoylmethane and enolates of acetoacetates and benzoyl acetatesand of dehydroacetic acid. Inorganic zinc compounds, such as zinc oxide,zinc hydroxide, zinc sulfide and zinc carbonate, may also be suitable.

In some embodiments, preference is given to zinc soaps such asbenzoates, alkanoates, alkanoates, stearates, oleates, laurates,palmitates, behenates, versatates, hydroxystearates, dihydroxystearates,p-tert-butylbenzoates, (iso)octanoates and 2-ethylhexanoate.

In some embodiments, organic aluminium, cerium or lanthanum carboxylatesand enolate compounds having a metal-O bond may also be used.

The zinc and metal compounds may be used in amounts of, for example,from 0.001 to 10, preferably from 0.01 to 8, and more preferably from0.01 to 5, parts by weight, based on 100 parts by weight of chlorinatedthermoplastic polymer, such as PVC.

In other embodiments, organotin stabilisers, carboxylates, mercaptidesand sulfides may be used. Examples of suitable compounds may be found inU.S. Pat. No. 4,743,640.

In some embodiments, the stabiliser component may be provided withadditional stabilisers, auxiliaries and processing agents, such asalkali metal and alkaline earth metal compounds, glidants (orlubricants), plasticisers, pigments, fillers, phosphites, thiophosphitesand thiophosphates, mercaptocarboxylic acid esters, epoxidised fattyacid esters, antioxidants, UV absorbers and light stabilisers, opticalbrighteners, impact strength modifiers and processing aids, gellingagents, antistatic agents, biocides, metal deactivators, fireproofingagents and propellants, and antifogging agents.

Further details of the stabilisers useful in the present thermoplasticcompositions described herein as well as other stabiliser components maybe found in EP768336 and EP 0492803.

The thermoplastic compositions of the present invention comprise atleast one lubricant (or at least one release agent). Some examples oflubricants suitable for use in the present invention include, but arenot limited to, fatty acids, fatty alcohols, fatty acid esters, fattyalcohol esters, fatty acid amides, polyol esters, polyethylene waxes,oxidised polyethylene waxes, polypropylene waxes, Fischer-Tropschparaffins, paraffin waxes, oligomeric esters (‘complex esters’),montanic acid esters, soaps, metal soaps of fatty acids, and metal soapsof montanic acids. An overview of other lubricants that may be useful inthe thermoplastic compositions of the present invention may be found in‘PVC Additives’, Hanser Publishing Munich, 2015, ISBN 978-1-56990-543-2.In some circumstances, it has been observed that the use of lubricantsand release agents have an influence on other properties of thethermoplastic composition such as antistatic and antifogging properties.

In order to provide the correct layer adhesion during FDM 3D printing,the present inventors have identified that processing with externallubricants normally associated with chlorinated thermoplastic polymers,such as PVC and CPVC, should not be used at ‘normal’ formulation levels,such as 0.1-2 phr max. In particular, the external lubricants shouldpreferably be used in amounts that complement the desired melt flow rateof the thermoplastic polymer or thermoplastic composition in 3Dprinting. Examples of external lubricants include, but are not limitedto, Fischer-Tropsch waxes, paraffin waxes, polyethylene waxes,esterified polyol esters (fully or partially) and other externallubricants known in the art.

The lubricants useful in the present invention include, but are notlimited to, Montan wax, fatty acid esters, PE waxes, amide waxes,chloroparaffins, glycerol esters and alkaline earth metal soaps. Fattyketones may also be used, as described in DE 42 04 887, and ofsilicone-based lubricants, as described in EP 225 261, or combinationsthereof, as described in FP 259 783.

The thermoplastic composition of the present invention requires asuitable balance of stabilising and lubricating properties compared withthe balance of stabilising and lubricating properties required withother plastic compositions used in non-3D printing applications. Thebalance of stabilising and lubricating properties should be chosen toachieve the desired interlayer adhesion properties of the thermoplasticcomposition.

Other components normally used with the chlorinated thermoplasticpolymer (such as PVC) compositions and processes may be included in thethermoplastic compositions of the present invention. These “other”components are disclosed for example, in ‘International PlasticsHandbook’, Hanser Publishing Munich, 2006, ISBN 3-56990-399-5; ‘PVCHandbook’, Hanser Publishing Munich, 2005, ISBN 3-446-22714-8 and in‘PVC Additives’, Hanser Publishing Munich, 2015, ISBN 978-1-56990-543-2.

In a preferred embodiment, the thermoplastic polymer is a stabilised PVCpolymer. Most preferably, the PVC polymer is a PVC homopolymer. The PVChomopolymer may have a K-value range of from 40 to 80. Preferably, thePVC homopolymer has a K-value range of 45 to 71. Most preferably, thePVC homopolymer has a K-value of about 45, about 50, about 57 or about71.

In situations where the thermoplastic polymers or thermoplasticcompositions have a higher viscosity, the final melt viscosity should beadjusted to a melt flow rate (MFR) of 0.5 to 30, preferably 2 to 20,more preferably 5 to 15, determined at 205° C. according to ASTM D1238.The viscosity may be adjusted to the desired viscosity by using, forexample, plasticisers and other additives.

In another preferred embodiment, the thermoplastic polymer is a blend ofpolymers. In this embodiment, the blend may be a mixture including PVCand another polymer, such as polyacrylate (such as Vinnolit 704).Alternatively, the polymer blend may be PVC with CPVC, ABS, ASA, CA, PC,PMMA, PBTP, TPU, SAN, SMA or polyketone. Compatibilisers may be used inthe polymer blend, if required.

In certain embodiments, additives commonly used in thermoplasticprocessing may be used. Such additives include, but are not limited to,fillers, reinforcing agents, calcium carbonate (ground natural andprecipitated), kaolin, talc, mica, barite, wollastonite, calciumsulfate, huntites and feldspars, as well as artificial fillers such asglass fibres, glass micro beads, fly ash products, magnesium hydroxide,aluminium hydroxide (ATH), wood-fibres and other plant fibres.

In certain embodiments, pigments may be added as required and gradessuitable for plastics should be used. Any organic and inorganic pigmentsand pigment preparations that are suitable for mixing with plastics andtolerate heating (i.e., does not decompose upon heating at 3D printingprocessing temperatures) may be used. For example, titanium dioxide isone preferred pigment. Heavy metal pigments and environmentally toxicmetal pigments, such as chromium, lead and cadmium-based pigments shouldbe avoided. Carrier additives complying with 3D printing processingrequirements may also be used. In certain embodiments, modifiers andprocessing aids may be used. Processing aids may include those based onlow, medium and high molecular weight acrylic polymer resins andcopolymers. In this embodiment, any one or more of: impact modifiers,flow modifiers and foam modifiers are preferably used. Preferably,acrylic impact modifiers may be used. These modifiers may be chlorinatedpolyethylenes (CPEs) or those based on acrylate ormethacrylate-butadiene-styrene (MBS) technology. The amounts at whichmodifiers may be used in the 3D printable compositions of the presentinvention would be dictated by the molecular weight of the thermoplasticpolymer component and/or the thermoplastic composition, and/or theviscosity thereof, as discussed herein.

In certain embodiments, the thermoplastic polymer or thermoplasticcomposition of the present invention may comprise plasticisers. Asuitable amount of plasticiser may be added to the thermoplastic polymeror thermoplastic composition to achieve the desired viscosity requiredfor 3D printing. In other embodiments, the amount of plasticiser addedmay be adjusted to provide thermoplastic polymer or thermoplasticcompositions that are capable of forming flexible filaments for FDM 3Dprinting processes. In one preferred embodiment, when PVC is used as athermoplastic polymer component in the thermoplastic composition, asuitable amount of plasticiser may be added to form a truly flexible PVCfilament for FDM 3D printing of 3D products.

A variety of plasticisers known in the art may be added to thethermoplastic polymer or thermoplastic composition. When plasticisersare incorporated into the thermoplastic composition, the preferredplasticisers are low volatility plasticisers, such as long-chainphthalates (e.g. DIDP, DINP), DINCH, trimellitates (e.g., TOTM, TIOTM),adipates, terephthalates, polymeric plasticisers (e.g. Edenol 1208),citrates, epoxidised oils (e.g., ESBO, HM 828) and other plasticisingcomponents that are compatible with chlorinated thermoplastic polymer,including PVC.

In certain embodiments, if desired, functional additives may be added tothe thermoplastic polymer or thermoplastic composition of the presentinvention. The functional additives may include, but are not limited to,flame retardants, anti-microbial additives, fungicides, blowing agents,conductivity agents, graphene, nanoparticles, other special functionaladditives known in the art and any mixture thereof.

EXAMPLES

The following PVC rigid compositions were prepared as dryblends,generally mixed to 120° C.; for the compositions containing plasticiser,the plasticiser was added at 60° C. and the dryblend then mixed to 110°C., as is standard procedure for PVC processing. Then the dry blendswere extruded on a Polylab laboratory twin screw extruder under standardextrusion conditions into filaments of 1.75 mm diameter.

The filaments were then 3D printed on a Reprap-style “Makergear MSeries” 3D printer into a 3D printing test piece(http://vww.thingiverse.com/thing:704409t) that allows assessment of 3Dprinting performance. The 3D printing parameters were adjusted to thefollowing conditions: Print speed 50 mm/s; printing temperature tocommence the print immediately once PVC is in the “hot-end”, set to190-290° C. manually on the host program; bed temperature to alsocommence the print immediately once PVC is in the “hot-end”, set to 100°C. manually on the host program. Stainless steel nozzle (required forPVC) size 0.4 mm.

Determination of MFR values were performed on a Davenport Daventest MFItester Type UT 731/016 (made in UK) according to ASTM D1238, ProcedureA, measured at 205° C. with a 2.16 kg nominal weight and a die of borediameter=2.0955+/−0.0051 mm, bore length=8+/−0.025 mm. Procedure A isused to determine the melt flow rate (MFR) of any thermoplasticmaterial. The units of measure are grams of material/10 minutes (g/10min). The unit is based on the measurement of the mass of material thatextrudes from the die over a given period of time. Procedure A isgenerally not recommended for PVC as it is generally used for materialshaving melt flow rates that fall between 0.15 and 50 g/10 min but it issuited for the chlorinated thermoplastic polymer or thermoplasticcompositions (e.g. PVC or PVC-containing compositions) required for 3Dprinting.

Layer adhesion was determined by 3D FDM printing the above testspecimens. If this was unsuccessful, the composition is deemed “not 3Dprintable”.

For compositions with good layer adhesion, a test sample for tensiletesting was made by, 3D printing test samples according to thedimensions of test specimen for ASTM D638.

The following non-limiting examples of the present invention will now bedescribed.

It would be understood that where appropriate, commercially availablecomponents may be used as a substitute of the components listed in thenon-limiting examples.

In the tables below the following components are listed:

PVC K 57=commercially available PVC with a K-value of 57

PVC K 50=commercially available PVC with a K-value of 50

Titanium dioxide=white pigment for plastics

Calcium carbonate=commercial filler as recommended for plastics

Sasol H1=commercial wax lubricant

Sasol C80=commercial wax lubricant

Honeywell Rheolub RL-165=commercial wax lubricant

Licowax PE520=commercial wax lubricant

Kaneka PA 40=commercial modifier

DINCH=commercial plasticiser

Vinnolit 704=commercial PVC copolymer

Licowax OP=commercial montan wax lubricant

Clearstrength W-300=commercial acrylic impact modifier

ESBO=commercially available epoxidised soybean oil, a liquidco-stabiliser

Naftosafe CP 3D-Vinyl stabilisers=stabiliser one packs, commerciallyavailable products of Chemson Pacific PTY LTD, 2 Capicure Drive, EasternCreek, NSW, Australia

Chlorinated Thermoplastic with Plasticiser

The following plasticiser-containing compositions shown in Table 1 wereprepared as above and the 3D printing properties assessed.

Chlorinated Thermoplastic with Plasticiser and separate acrylic modifier

TABLE 1 Chlorinated Thermoplastic with Plasticiser Example ComparisonExample PHR A I B PVC K 57 100.00 100.00 100.00 Titanium dioxide 4.004.00 4.00 Calcium carbonate 20.00 20.00 20.00 Sasol H1 0.20 Naftosafe CP3D-Vinyl 70 3.44 3.44 Naftosafe CP 3D-Vinyl 47 7.17 Sasol C80 0.40Honeywell Rheolub RL-165 0.10 0.10 0.10 Licowax PE520 0.09 0.09 0.09Kaneka PA40 2.94 2.94 3.00 DINCH 20.00 20.00 20.00 MFR-value [at 205° C.in 12.3 0.4 9.2 g/10 mins]

The compositions according the present invention provided a 3D printablefilament whereas the normally lubricated formulation (comparison)resulted in unsuitable layer adhesion and was thus not considered to be3D printable. Increasing the amounts of stabilising components in thecomposition without adjusting the external lubricants allowed for a 3Dprintable composition.

Chlorinated Thermoplastic with Plasticiser and PVC-grafted AcrylicModifier

In the following compositions shown in Table 2 the acrylic component isa grafted acrylic-PVC polymer (Vinnolit 704).

TABLE 2 Chlorinated Thermoplastic with Plasticiser and PVC-graftedAcrylic Modifier PHR Example C Comparison II PVC K 57 100.00 100.00Vinnolit 704 10.00 10.00 Titanium dioxide 4.00 4.00 Calcium carbonate20.00 20.00 Naftosafe CP 3D-Vinyl 70 4.73 4.73 Honeywell Rheolub RL-1650.14 0.14 Licowax PE520 0.12 0.12 Licowax OP 0.40 DINCH 20.00 MFR-value[at 205° C. in 10.6 0.7 g/10 mins]

The formulations according to the present invention provided a 3Dprintable filament even despite increased stabilising components incombination with the PVC copolymer. Removing the plasticiser and addingexternal lubricant (comparison) resulted in a better filament extrusionbut gave virtually no layer adhesion, thus a non-3D-printablecomposition.

Chlorinated Thermoplastic with no Plasticiser and Low Viscosity PVC

The following formulations shown in Table 3 contain no plasticiser, butare based on a low viscosity PVC.

TABLE 3 Chlorinated Thermoplastic with no Plasticiser and Low ViscosityPVC PHR Example D Comparison III PVC K 57 100.00 PVC K 50 100.00Clearstrength W-300 3.00 3.00 Naftosafe CP 3D-Vinyl 81 3.40 3.40 ESBO5.00 5.00 MFR-value [at 205° C. in 9.3 4.8 g/10 mins]

The compositions according to the present invention provided a 3Dprintable filament which resulted in 3D printed product of excellentdefinition, increasing the PVC viscosity without otherviscosity-reducing components in this composition (comparison) resultedin significant warping and worse definition.

Other embodiments and uses of this invention will be apparent to thosehaving ordinary skill in the art upon consideration of the specificationand figures of the invention disclosed herein. The specification givenshould be considered as exemplary only, and it is contemplated that theappended claims will cover any other such embodiments or modificationsthat fall within the scope of the invention disclosed herein.

The invention claimed is:
 1. A thermoplastic polymer for additivemanufacturing, wherein the thermoplastic polymer is derived from achlorinated monomer unit, wherein the thermoplastic polymer has a meltflow rate (MFR) suitable for additive manufacturing, wherein the MFR isfrom 5 to 30, as determined at 205° C. according to ASTM D1238.
 2. Athermoplastic composition for additive manufacturing, wherein thethermoplastic composition comprises at least one thermoplastic polymerderived from a chlorinated monomer unit and at least one stabiliser,wherein the thermoplastic composition has a melt flow rate (MFR)suitable for additive manufacturing, wherein the MFR is from 5 to 30, asdetermined at 205° C. according to ASTM D1238.
 3. The thermoplasticpolymer of claim 1, wherein the thermoplastic polymer further comprisesat least one lubricant.
 4. The thermoplastic polymer of claim 1, whereinthe thermoplastic polymer has a tensile strength from 15 to 60 MPa,measured according to ASTM D638.
 5. The thermoplastic polymer of claim4, wherein the tensile strength of the thermoplastic polymer is from 20to 60 MPa, measured according to ASTM D638.
 6. The thermoplastic polymerof claim 1, wherein the thermoplastic polymer is polyvinyl chloride(PVC) or chlorinated polyvinyl chloride (CPVC).
 7. The thermoplasticcomposition of claim 2, further comprising one or more thermoplasticmaterials selected from polyolefins, polyhydroxyalkanoates (PHA),polyesters, polyester elastomers, polyamides (PA), polystyrenes,polyketones, polyvinyl chlorides (PVC), chlorinated polyvinyl chlorides(CPVC), polyvinylidene chlorides, acrylic resins, vinyl ester resins,polyurethane elastomers and polycarbonates.
 8. The thermoplasticcomposition of claim 7, wherein the polyolefin is linear low-densitypolyethylene, low-density polyethylene, middle-density polyethylene,high-density polyethylene, ethylene-vinyl acetate copolymer,ethylene-alkyl acrylate copolymer, ethylene-propylene copolymer,polypropylene, propylene-α-olefin copolymer, polybutene, polypentene,chloropolyethylene, chloropolypropylene, or combinations of two or morethereof.
 9. The thermoplastic composition of claim 7, wherein thethermoplastic polymer is polyvinyl chloride and has a K-value of betweenabout 40 and about
 80. 10. The thermoplastic composition of claim 2,wherein the thermoplastic composition comprises any one or more ofplasticisers, compatibilizers, fillers, reinforcing agents, pigments,modifiers and processing aids, release agents, flame retardants,anti-microbial additives and fungicides, blowing agents, conductivityagents, wood fibres, bamboo, chalk, metals and other additives.
 11. Thethermoplastic composition of claim 2, wherein the at least onestabilizer is substantially free of lead, cadmium and/or barium.
 12. Thethermoplastic composition of claim 2, wherein the thermoplasticcomposition is provided in the form of powders, powder-blends, pellets,granules or filaments.
 13. A 3D product formed by additivemanufacturing, wherein the 3D product comprises the thermoplasticpolymer of claim
 1. 14. The thermoplastic polymer of claim 1, whereinthe thermoplastic polymer is polyvinyl chloride and has a K-value ofbetween about 40 and about
 80. 15. The thermoplastic polymer of claim 1,wherein the thermoplastic polymer is provided in the form of powders,powder-blends, pellets, granules or a filament.
 16. The thermoplasticcomposition of claim 2, wherein the thermoplastic composition furthercomprises at least one lubricant.
 17. The thermoplastic composition ofclaim 2, wherein the thermoplastic composition has a tensile strengthfrom 15 to 60 MPa, measured according to ASTM D638.
 18. Thethermoplastic composition of claim 17, wherein the tensile strength ofthe thermoplastic composition is from 20 to 60 MPa, measured accordingto ASTM D638.
 19. The thermoplastic composition of claim 2, wherein thethermoplastic polymer is polyvinyl chloride (PVC) or chlorinatedpolyvinyl chloride (CPVC).
 20. The thermoplastic composition of claim19, wherein the alkyl groups of the alkyl acrylates and alkylmethacrylates have from 1 to 10 carbon atoms.
 21. The thermoplasticcomposition of claim 19, wherein at least a portion of the carboxylicacid groups in the copolymer are neutralized to salts containing alkalimetal cations, alkaline earth metal cations, transition metal cations,or combinations thereof.
 22. The thermoplastic polymer of claim 6,wherein the thermoplastic polymer is copolymerised with comonomer unitsselected from ethylenically unsaturated carboxylic acids, ethylenicallyunsaturated carbonates, ethylenically unsaturated urethanes,ethylenically unsaturated alcohols, ethylenically unsaturated aromatics,or combinations of two or more thereof.
 23. The thermoplastic polymer ofclaim 6, wherein the thermoplastic polymer is copolymerized withcomonomer units selected from alkyl acrylates, alkyl methacrylates,ethylene vinyl alcohols, vinyl acetates, styrenes, and hydroxyalkanoicacid wherein the hydroxyalkanoic acids have five or fewer carbon atoms,or combinations of two or more thereof.
 24. The thermoplastic polymer ofclaim 23, wherein the alkyl groups of the alkyl acrylates and alkylmethacrylates have from 1to 10 carbon atoms.
 25. The thermoplasticpolymer of claim 22, wherein at least a portion of the carboxylic acidgroups in the copolymer are neutralized to salts containing alkali metalcations, alkaline earth metal cations, transition metal cations, orcombinations thereof.
 26. The thermoplastic composition of claim 19,wherein the thermoplastic polymer is copolymerised with comonomer unitsselected from ethylenically unsaturated carboxylic acids, ethylenicallyunsaturated carbonates, ethylenically unsaturated urethanes,ethylenically unsaturated alcohols, ethylenically unsaturated aromatics,or combinations of two or more thereof.
 27. The thermoplasticcomposition of claim 19, wherein the thermoplastic polymer iscopolymerized with comonomer units selected from alkyl acrylates, alkylmethacrylates, ethylene vinyl alcohols, vinyl acetates, styrenes, andhydroxyalkanoic acid wherein the hydroxyalkanoic acids have five orfewer carbon atoms, or combinations of two or more thereof.
 28. Thethermoplastic composition of claim 27, wherein at least a portion of thecarboxylic acid groups in the copolymer are neutralized to saltscontaining alkali metal cations, alkaline earth metal cations,transition metal cations, or combinations thereof.